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Pse-in-One 2.0: An Improved Package of Web Servers for Generating Various Modes of Pseudo Components of DNA, RNA, and Protein Sequences 被引量:12
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作者 Bin Liu Hao Wu Kuo-Chen Chou 《Natural Science》 2017年第4期67-91,共25页
Pse-in-One 2.0 is a package of web-servers evolved from Pse-in-One (Liu, B., Liu, F., Wang, X., Chen, J. Fang, L. & Chou, K.C. Nucleic Acids Research, 2015, 43:W65-W71). In order to make it more flexible and compr... Pse-in-One 2.0 is a package of web-servers evolved from Pse-in-One (Liu, B., Liu, F., Wang, X., Chen, J. Fang, L. & Chou, K.C. Nucleic Acids Research, 2015, 43:W65-W71). In order to make it more flexible and comprehensive as suggested by many users, the updated package has incorporated 23 new pseudo component modes as well as a series of new feature analysis approaches. It is available at http://bioinformatics.hitsz.edu.cn/Pse-in-One2.0/. Moreover, to maximize the convenience of users, provided is also the stand-alone version called “Pse-in-One-Analysis”, by which users can significantly speed up the analysis of massive sequences. 展开更多
关键词 PSEUDO componentS DNA sequenceS RNA sequenceS Protein sequenceS
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Disassembly sequence planning using component-joint graph and ant colony optimization
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作者 Zheng Menglei Tian Ling Liu Beibei 《Computer Aided Drafting,Design and Manufacturing》 2016年第1期54-57,共4页
Disassembly sequence planning is an important step of mechanical maintenance. This article presents an integrated study about the generation and optimizing algorithm of the disassembly sequence. Mechanical products ar... Disassembly sequence planning is an important step of mechanical maintenance. This article presents an integrated study about the generation and optimizing algorithm of the disassembly sequence. Mechanical products are divided into two categories of components and connectors. The article uses component-joint graph to represent assembly constraints, including the incidence constraints are represented by incidence matrix and the interference constraints are represented by interference constraints. The inspiring factor and pheromone matrix are calculated according to assembly constraints. Then the ant generates its own disassembly sequences one by one and updates the inspiring factor and pheromone matrix. After all iterations, the best disassembly sequence planning of components and connectors are given. Finally, an application instance of the disassembly sequence of the jack is presented to illustrate the validity of this method. 展开更多
关键词 disassembly sequence planning component-joint graph ant colony algorithms
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Unexpected metastasis of intraductal papillary neoplasm of the bile duct without an invasive component to the brain and lungs:A case report 被引量:6
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作者 Nguyen Hai Nam Kojiro Taura +7 位作者 Masashi Kanai Keita Fukuyama Norimitsu Uza Hirona Maeda Yojiro Yutaka Toyofumi F Chen-Yoshikawa Manabu Muto Shinji Uemoto 《World Journal of Gastroenterology》 SCIE CAS 2020年第3期366-374,共9页
BACKGROUND Despite an expanding number of studies on intraductal papillary neoplasm of the bile duct(IPNB),distant metastasis remains unexplained especially in cases of carcinoma in situ.In the present study,we report... BACKGROUND Despite an expanding number of studies on intraductal papillary neoplasm of the bile duct(IPNB),distant metastasis remains unexplained especially in cases of carcinoma in situ.In the present study,we report a rare and interesting case of IPNB without invasive components that later metastasized to lungs and brain.CASE SUMMARY A 69-year-old male was referred to our hospital due to suspected cholangiocarcinoma.Laboratory tests on admission reported a mild elevation of alkaline phosphatase,γ-glutamyl transpeptidase,and total bilirubin in serum.Endoscopic retrograde cholangiography revealed a filling defect in the common bile duct(CBD)extending to the left hepatic duct.Peroral cholangioscopy delineated a tumor in the CBD that had a papillary pattern.Multidetector computed tomography and magnetic resonance cholangiopancreatography detected partial blockage ot interlude in the CBD leading to cholestasis without evidence of metastasis.Therefore,a diagnosis of IPNB cT1N0M0 was established.Left hepatectomy with bile duct reconstruction was performed.Pathological examination confirmed an intraepithelial neoplasia pattern without an invasive component and an R0 resection achievement.The patient was monitored carefully by regular examinations.However,at 32 mo after the operation,a 26 mm tumor in the lungs and a 12 mm lesion in the brain were detected following a suspicious elevated CA 19-9 level.Video-assisted thoracoscopic surgery of left upper lobectomy and stereotactic radiotherapy are indicated.In addition to histopathological results,a genomic profiling analysis using whole exome sequencing subsequently confirmed lung metastasis originating from bile duct cancer.CONCLUSION This case highlights the important role of genomic profiling analysis using whole exome sequencing in identifying the origin of metastasis in patients with IPNB. 展开更多
关键词 Intraductal papillary neoplasm of the bile duct Distant metastasis Invasive component Whole exome sequencing CA 19-9 Case report
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Performance improvement of software component with partial evaluation
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作者 毛宏燕 黄林鹏 李明禄 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2008年第1期95-99,共5页
To avoid the complexity and inefficiency for specific applications of the current software architecture, a novel approach using partial evaluation is proposed to improve the running performance of components. The gene... To avoid the complexity and inefficiency for specific applications of the current software architecture, a novel approach using partial evaluation is proposed to improve the running performance of components. The generic program was specialized into domain-specific realization for the known knowledge and environments. The syntax and semantic(adj.) were analyzed based on byte code instruction sequences, and partial evaluation rules depicted how to perform the specialization. The partial evaluation for object-oriented programs was implemented. The experimental results show that partial evaluation is effective to speed up the running efficiency. The more generality and scalability can be obtained by the integration of partial evaluation with the favorable design mechanisms and compiler optimization technology. 展开更多
关键词 partial evaluation running efficiency component byte code instruction sequence
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An Efficient and Cost-Saving Component Scheduling Algorithm Using High Speed Turret Type Machines for a Board Containing Multiple PCBs
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作者 Wei-Shung Chang Chiuh-Cheng Chyu 《Intelligent Control and Automation》 2011年第2期86-94,共9页
This paper considers a material constrained component scheduling problem during the high speed surface mount manufacturing stage in printed circuit board (PCB) assembly, where each piece of board contains an even numb... This paper considers a material constrained component scheduling problem during the high speed surface mount manufacturing stage in printed circuit board (PCB) assembly, where each piece of board contains an even number of identical PCBs. To accomplish the production, material requirements must be predetermined and incorporated as restraints into the scheduling problem, which has the objective of minimizing production completion time (makespan). A solution procedure is developed based on the following strategies: 1) Each machine is responsible for the same PCBs of each piece, 2) Components of the same types may use one or more feeder locations, 3) Component types are clustered based on their suitable placement speeds, 4) A heuristic using a bottom-up approach is applied to determine the component placement sequence and the feeder location assignment for all machines. Velocity estimate functions of the turret, XY table, and feeder carriage were derived based on empirical data. An experiment using Fuji CP732E machines was conducted on two real life instances. Experimental results indicate that our method performs 32.96% and 10.60% better than the Fuji-CP software for the two instances, in terms of the makespan per piece of board. 展开更多
关键词 Printed Circuit Boards Assembly Surface Mount Technology Heuristics component Placement sequence FEEDER Location Assignment
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Feature-driven topology optimization method preserving component sequences considering turning angle constraint
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作者 Dongsheng Jia Lei Liu +2 位作者 Jihong Zhu Yu Zhang Vassili Toropov 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2024年第10期41-56,共16页
Component sequence preservation is an intrinsic requirement in typical engineering applications, such as deployable chain-likestructures, 3D printing structures with contour-parallel toolpaths, additive manufacturing ... Component sequence preservation is an intrinsic requirement in typical engineering applications, such as deployable chain-likestructures, 3D printing structures with contour-parallel toolpaths, additive manufacturing of continuous fibre-reinforcedpolymer structures, customized stents, and soft robotics parts. This study presents a feature-driven method that preservescomponent sequences accounting for engineering requirements. The chain-of-bars design variables setting scheme is developedto realize the sequential component’s layout, which sets the current bar’s end point as the next bar’s start point. The total lengthof the printing path is constrained to reduce the consumption of material accurately. Also, the angle between adjacent bars isconstrained to avoid sharp angles at the turning point of the 3D printing path. Next, the sensitivity analysis considering theinter-dependence of substructures is performed. Several numerical examples are given to demonstrate the validity and merits ofthe proposed method in designing structures preserving component sequences. 展开更多
关键词 Topology optimization component sequence preservation Chain-like structures Feature-driven method Additive manufacturing
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Fully Decoupled Branch Energy Balancing Control Method for Modular Multilevel Matrix Converter Based on Sequence Circulating Components
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作者 Zexin Zhao Weijiang Chen +5 位作者 Zhichang Yang Guoliang Zhao Bin Han Yunfei Xu Nianwen Xiang Shulai Wang 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2024年第1期235-247,共13页
The modular multilevel matrix converter(M3C)is a potential frequency converter for low-frequency AC transmission.However,capacitor voltage control of high-voltage and largecapacity M3C is more difficult,especially for... The modular multilevel matrix converter(M3C)is a potential frequency converter for low-frequency AC transmission.However,capacitor voltage control of high-voltage and largecapacity M3C is more difficult,especially for voltage balancing between branches.To solve this problem,this paper defines sequence circulating components and theoretically analyzes the influence mechanism of different sequence circulating components on branch capacitor voltage.A fully decoupled branch energy balancing control method based on four groups of sequence circulating components is proposed.This method can control capacitor voltages of nine branches in horizontal,vertical and diagonal directions.Considering influences of both circulating current and voltage,a cross decoupled control is designed to improve control precision.Simulation results are taken from a low-frequency transmission system based on PSCAD/EMTDC,and effectiveness and precision of the proposed branch energy balancing control method are verified in the case of nonuniform parameters and an unbalanced power system. 展开更多
关键词 Branch energy balancing control decoupled control low-frequency AC transmission modular multilevel matrix converter(M3C) sequence circulating components
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基于价值评估的废旧产品拆卸序列与拆卸深度决策
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作者 张华 殷俊鸿 +3 位作者 鄢威 马峰 江志刚 朱硕 《组合机床与自动化加工技术》 北大核心 2025年第1期143-149,共7页
为解决拆卸序列规划(disassembly sequence planning,DSP)中存在的复杂模型构建难题、组合爆炸以及拆解深度决策不合理等问题,提出了一种基于知识图谱属性图模块化的改进方法实现废旧产品拆卸信息的获取,并提出了一种基于剩余回收效益... 为解决拆卸序列规划(disassembly sequence planning,DSP)中存在的复杂模型构建难题、组合爆炸以及拆解深度决策不合理等问题,提出了一种基于知识图谱属性图模块化的改进方法实现废旧产品拆卸信息的获取,并提出了一种基于剩余回收效益评估的拆解序列与拆解深度综合决策方法。首先,通过分析废旧产品的拆卸特征以及产品内部零部件的信息和拆卸联接关系,构建支持拆解的模块化属性图模型;[JP2]其次,采用组合赋权及改进的TOPSIS灰色关联分析法构建了零件回收综合评价模型的多属性决策模型,对产品综合内部零部件剩余回收效益进行排序;再次,提出了基于改进遗传-粒子群算法的完全拆解序列生成方法,并结合剩余回收效益值进行废旧产品零件的拆解深度决策。以废旧汽车动力电池包为例对上述模型和方法进行了验证,证明了该方法的可行性和高效性。 展开更多
关键词 废旧产品 知识图属性图模型 零件回收综合评价 拆卸序列优化 拆卸深度决策
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基于波形相似性的柔性互联配电网短路故障区段定位方法
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作者 陈继明 陈文淙 +2 位作者 仉志华 于馨玮 徐乾 《电力工程技术》 北大核心 2025年第1期104-114,共11页
由于柔性多状态开关(soft normal open point,SNOP)复杂的控制策略及其弱馈特性,传统配电网故障定位方法难以适用于柔性互联配电网(flexible distribution network,FDN)。因此,文中提出一种利用电流正序分量波形相似性进行FDN故障区段... 由于柔性多状态开关(soft normal open point,SNOP)复杂的控制策略及其弱馈特性,传统配电网故障定位方法难以适用于柔性互联配电网(flexible distribution network,FDN)。因此,文中提出一种利用电流正序分量波形相似性进行FDN故障区段定位的方法。首先,针对SNOP的典型控制策略,分析FDN的短路故障特征。其次,计算配电网中不同故障位置电流正序分量的Tanimoto系数,通过对比不同位置的电流正序分量波形相似性,构建FDN短路故障定位判据,并通过Teager能量算子(Teager energy operation,TEO)实现故障时刻的精确定位,利用智能配电终端(smart terminal unit,STU)传递信息。最后,通过建模仿真对所提方法进行分析验证,结果表明该方法能够对故障区段进行准确定位,不受故障位置、故障类型、过渡电阻、采样频率及通信延时等因素的影响,验证了该方法的可行性与有效性。 展开更多
关键词 柔性互联配电网(FDN) 柔性多状态开关(SNOP) 故障分析 波形相似性 故障定位 电流正序分量
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逆变类电源接入条件下传统方向元件适应性分析
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作者 高厚磊 袁通 +1 位作者 彭放 李林 《电力自动化设备》 北大核心 2025年第2期150-158,共9页
逆变类电源(IBS)接入场景下,传统方向元件逐渐暴露出适应性问题,目前缺乏全面的理论分析。为此,结合逆变器控制策略和我国对IBS低电压穿越的最新要求,推导得出了IBS的故障特征;在此基础上,深入分析IBS和负荷在传统方向元件下所呈现出的... 逆变类电源(IBS)接入场景下,传统方向元件逐渐暴露出适应性问题,目前缺乏全面的理论分析。为此,结合逆变器控制策略和我国对IBS低电压穿越的最新要求,推导得出了IBS的故障特征;在此基础上,深入分析IBS和负荷在传统方向元件下所呈现出的相位特征,进一步考虑多种影响因素,定量给出了含IBS线路中传统方向元件的角度变化范围;利用PSCAD/EMTDC和现场录波数据验证理论分析的正确性。理论分析和仿真结果表明,IBS接入场景下,传统方向元件建立的理论基础不再成立,易导致误判发生,不满足继电保护的要求。 展开更多
关键词 逆变类电源 正序故障分量方向元件 90°接线方向元件 适应性分析 低电压穿越 继电保护
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动态电压恢复器的分数阶正负序解耦控制策略
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作者 吴朝俊 王振跃 +1 位作者 杨宁宁 邵文权 《电力工程技术》 北大核心 2025年第1期60-68,共9页
为了改善动态电压恢复器(dynamic voltage restorer,DVR)治理不对称电压暂降故障的性能,文中提出基于瞬时对称分量法的分数阶正负序解耦控制策略,并将其应用于三相四桥臂逆变器DVR系统中。首先,利用对称分量法得到DVR系统的分序解耦数... 为了改善动态电压恢复器(dynamic voltage restorer,DVR)治理不对称电压暂降故障的性能,文中提出基于瞬时对称分量法的分数阶正负序解耦控制策略,并将其应用于三相四桥臂逆变器DVR系统中。首先,利用对称分量法得到DVR系统的分序解耦数学模型。其次,针对传统对称分量法不适用于系统暂态过程分析的问题,采用瞬时对称分量法得到不对称电压电流信号瞬时值的正负零序分量,并独立设计三序分量的电压电流双闭环比例积分(proportional-integral,PI)控制策略。然后,将整数阶正负序解耦控制策略推广到分数阶,并利用频域方法与增益变化时的鲁棒性条件相结合对相关参数进行校正。最后,通过仿真结果验证分数阶正负序解耦控制策略应用于DVR系统的可行性,且与传统正负序解耦控制相比较,所提策略具有更好的动态响应速度与抗干扰性能。 展开更多
关键词 电压暂降 动态电压恢复器(DVR) 三相四桥臂逆变器 瞬时对称分量法 正负序解耦控制 分数阶控制
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基于新型正序故障分量综合阻抗的有源配电网纵联保护
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作者 王亚兵 童晓阳 +2 位作者 赵紫斌 董星星 Sohail Manzoor 《电力自动化设备》 北大核心 2025年第2期103-109,共7页
分布式电源接入配电网改变了传统配电网的拓扑结构,使故障特性发生了改变,常规的配电网电流保护将失去选择性。针对该问题,提出一种基于新型正序故障分量综合阻抗的有源配电网纵联保护方法。对不同类型分布式电源接入的线路发生区/内外... 分布式电源接入配电网改变了传统配电网的拓扑结构,使故障特性发生了改变,常规的配电网电流保护将失去选择性。针对该问题,提出一种基于新型正序故障分量综合阻抗的有源配电网纵联保护方法。对不同类型分布式电源接入的线路发生区/内外故障时的正序故障电压、电流故障特征进行分析。利用区段两端电压、电流正序故障分量,构造两侧的线路推算阻抗,将它们相减后得到新型的综合阻抗。将综合阻抗与线路阻抗之比作为阻抗系数,进而构造区、内外短路故障的保护判据。通过大量仿真验证了所提保护算法的有效性,其能够准确地检测出短路故障,不受故障类型、故障位置、分布式电源类型、渗透率、分布式电源退出的影响,具有较强的抗过渡电阻能力,且灵敏度较高。 展开更多
关键词 有源配电网 继电保护 纵联保护 分布式电源 正序故障分量 新型综合阻抗 短路故障
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Cost-effective low-coverage whole-genome sequencing assay for the risk stratification of gastric cancer 被引量:2
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作者 Li-Ping Ye Xin-Li Mao +11 位作者 Xian-Bin Zhou Yi Wang Shi-Wen Xu Sai-Qin He Zi-Liang Qian Xiao-Gang Zhang Li-Juan Zhai Jin-Bang Peng Bin-Bin Gu Xiu-Xiu Jin Ya-Qi Song Shao-Wei Li 《World Journal of Gastrointestinal Oncology》 SCIE 2022年第3期690-702,共13页
BACKGROUND Gastric cancer(GC), a multifactorial disease, is caused by pathogens, such as Helicobacter pylori(H. pylori) and Epstein-Barr virus(EBV), and genetic components.AIM To investigate microbiomes and host genom... BACKGROUND Gastric cancer(GC), a multifactorial disease, is caused by pathogens, such as Helicobacter pylori(H. pylori) and Epstein-Barr virus(EBV), and genetic components.AIM To investigate microbiomes and host genome instability by cost-effective,low-coverage wholegenome sequencing,as biomarkers for GC subtyping.METHODS Samples from 40 GC patients were collected from Taizhou Hospital,Zhejiang Province,affiliated with Wenzhou Medical University.DNA from the samples was subjected to low-coverage wholegenome sequencing with a median genome coverage of 1.86×(range:1.03×to 3.17×) by Illumina×10,followed by copy number analyses using a customized bioinformatics workflow ultrasensitive chromosomal aneuploidy detector.RESULTS Of the 40 GC samples,20 (50%) were found to be enriched with microbiomes.EBV DNA was detected in 5 GC patients (12.5%).H.pylori DNA was found in 15 (37.5%) patients.The other 20(50%) patients were found to have relatively higher genomic instability.Copy number amplifications of the oncogenes,ERBB2 and KRAS,were found in 9 (22.5%) and 7 (17.5%) of the GC samples,respectively.EBV enrichment was found to be associated with tumors in the gastric cardia and fundus.H.pylori enrichment was found to be associated with tumors in the pylorus and antrum.Tumors with elevated genomic instability showed no localization and could be observed in any location.Additionally,H.pylori-enriched GC was found to be associated with the Borrmann type Ⅱ/Ⅲ and gastritis history.EBV-enriched GC was not associated with gastritis.No statistically significant correlation was observed between genomic instability and gastritis.Furthermore,these three different molecular subtypes showed distinct survival outcomes (P=0.019).EBV-positive tumors had the best prognosis,whereas patients with high genomic instability (CIN+) showed the worst survival.Patients with H.pylori infection showed intermediate prognosis compared with the other two subtypes.CONCLUSION Thus,using low-coverage whole-genome sequencing,GC can be classified into three categories based on disease etiology;this classification may prove useful for GC diagnosis and precision medicine. 展开更多
关键词 Gastric cancer Whole-genome sequencing Helicobacter pylori infections Epstein-Barr virus infections Genetic components Precision medicine
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Detection Scheme of Positive Sequence Components Based on Operation Period Delay Filter 被引量:1
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作者 Liwei Du Liansong Xiong +3 位作者 Mingxian Li Zhen Tang Liancheng Xiu Xun Ma 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2023年第1期235-243,共9页
Fast and accurate acquisition of positive sequence components of unbalanced grid voltage is an essential requirement to ensure the safety operation of the grid-connected inverter.To improve the extraction speed of pos... Fast and accurate acquisition of positive sequence components of unbalanced grid voltage is an essential requirement to ensure the safety operation of the grid-connected inverter.To improve the extraction speed of positive sequence components of unbalanced voltage,this study proposes a sampling period delay filter(SPDF)to quickly separate positive and negative sequence components by delaying two sampling periods of grid voltage in dq frame.With the SPDF method,only one coordinate transformation is required and the computational burden can be reduced apparently.Then,the noise immunity performance of the proposed SPDF algorithm is investigated;and the corresponding solution,operation period delay filter(OPDF),can guarantee the desired fast response performance under the premise of limiting the amplified noise within the acceptable range.Finally,the feasibility and priority of the above two algorithms have been verified by the simulation and experimental results. 展开更多
关键词 Noise immunity positive sequence components second harmonic components SPDF/OPDF algorithm unbalanced grid voltage
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Adaptive Three-phase Estimation of Sequence Components and Frequency Using H∞ Filter Based on Sparse Model 被引量:1
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作者 Umamani Subudhi Harish Kumar Sahoo Sanjeev Kumar Mishra 《Journal of Modern Power Systems and Clean Energy》 SCIE EI CSCD 2020年第5期981-990,共10页
The estimation of sequence or symmetrical components and frequency in three-phase unbalanced power system is of great importance for protection and relay.This paper proposes a new H∞filter based on sparse model to tr... The estimation of sequence or symmetrical components and frequency in three-phase unbalanced power system is of great importance for protection and relay.This paper proposes a new H∞filter based on sparse model to track the sequence components and the frequency of three-phase unbalanced power systems.The inclusion of sparsity improves the error convergence behavior of estimation model and hence short-duration non-stationary PQ events can easily be tracked in the time domain.The proposed model is developed using l1 norm penalty in the cost function of H∞filter,which is quite suitable for estimation across all the three phases of an unbalanced system.This model uses real state space modeling across three phases to estimate amplitude and phase parameters of sequence components.However,frequency estimation uses complex state space modeling and Clarke transformation generates a complex measurement signal from the unbalanced three-phase voltages.The state vector used for frequency estimation consists of two state variables.The proposed sparse model is tested using distorted three-phase signals from IEEE-1159-PQE database and the data generated from experimental laboratory setup.The analysis of absolute and mean square error is presented to validate the performance of the proposed model. 展开更多
关键词 sequence component Clarke transformation H∞filter state space model
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Application of Six-Sequence Fault Components in Fault Location for Joint Parallel Transmission Line 被引量:3
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作者 范春菊 蔡华嵘 郁惟镛 《Tsinghua Science and Technology》 SCIE EI CAS 2005年第2期247-253,共7页
A new fault location method based on six-sequence fault components was developed for parallel lines based on the fault analysis of a joint parallel transmission line. In the six-sequence fault network, the ratio of ... A new fault location method based on six-sequence fault components was developed for parallel lines based on the fault analysis of a joint parallel transmission line. In the six-sequence fault network, the ratio of the root-mean square value of the fault current from two terminals is the function of the line imped- ance, the system impedance, and the fault distance away from the buses. A fault location equation is given to relate these factors. For extremely long transmission lines, the distributed capacitance is divided by the fault point and allocated to the two terminals of the transmission line in a lumped parameter to eliminate the influence of the distributed capacitance on the location accuracy. There is no limit on fault type and syn- chronization of the sampling data. Simulation results show that the location accuracy is high with an average error about 2%, and it is not influenced by factors such as the load current, the operating mode of the power system, or the fault resistance. 展开更多
关键词 fault location joint parallel line six-sequence components two-terminal
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Study on the Effect of Variation of Flow in Sequencing Batch Reactor Using PCA and ANOVA
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作者 Govindasamy Vijayan R. Saravanane T. Sundararajan 《Journal of Geoscience and Environment Protection》 2017年第4期56-74,共19页
Wastewater treatment using Sequencing Batch Reactor (SBR) technology is one of the state-of-the art wastewater management systems. In this technology equalization, biological treatment and secondary clarification are ... Wastewater treatment using Sequencing Batch Reactor (SBR) technology is one of the state-of-the art wastewater management systems. In this technology equalization, biological treatment and secondary clarification are performed in a single reactor in a time control sequence. SBR system is idler for the areas where the available land is limited, since it operates in less space and very cost effective even on small scales. The control of the operational parameters during the process of biological wastewater treatment is often complicated due to the dynamic change in the composition and characteristics of the raw wastewater, flow rates and other parameters influencing the complex nature of the treatment process and the process in SBR has a unique cyclic batch operation. The performance of the SBR was studied using pilot and real plant at Puducherry. The parameters considered in this study are flow, Mixed Liquor Suspended Solids (MLSS), pH, temperature, influent and effluent of Total Suspended Solids (TSS), Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD). As a part of the study, the effect of constant flow and varying flow on the organic loading of the influent TSS, BOD and COD and their influence on the organic load of the effluent parameters were examined to identify the level of significance of the parameters in relation to the flow. The impact of flow on other parameters was also examined. The experimental data obtained from pilot and real plants were analyzed using multi variate statistical analyses like correlation analysis, Principal Component Analysis (PCA) and Analysis of variance (ANOVA). The statistical analysis revealed that constant flow had no significant role and the influent parameters alone had the critical role, whereas varying flow as well as the influent parameters had the significant role on the performance of SBR. 展开更多
关键词 sequencING BATCH Reactor (SBR) Mixed LIQUOR Suspended Solids (MLSS) Principal component ANALYSIS (PCA) ANALYSIS of Variance (ANOVA)
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考虑铁心结构的三相变压器励磁涌流和角型绕组环流分析 被引量:1
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作者 柴济民 郑玉平 潘书燕 《电力科学与技术学报》 CAS CSCD 北大核心 2024年第2期91-100,共10页
基于三相组式、五柱式和三柱式铁心结构变压器的磁路特征和运行方程,首先,提出运用星形侧零序电流和电压来拟合角型绕组环流的数值方法,并进一步研究不同铁心结构变压器的角型绕组环流和励磁涌流的特点;然后,进行软件仿真和现场录波以... 基于三相组式、五柱式和三柱式铁心结构变压器的磁路特征和运行方程,首先,提出运用星形侧零序电流和电压来拟合角型绕组环流的数值方法,并进一步研究不同铁心结构变压器的角型绕组环流和励磁涌流的特点;然后,进行软件仿真和现场录波以验证该数值方法的有效性,可判断三相组式和五柱式变压器的各相绕组差流即为对应相的励磁涌流,而三柱式变压器某相的绕组差流并不是对应相的励磁电流;最后,进一步的理论分析与仿真验证表明,在3类铁心结构的变压器从星形侧空载合闸时,星形侧任意两相的线电流之差可以认为是这两相等效磁路的励磁涌流之差。研究结论可以为不同铁心结构三相变压器的励磁涌流识别提供依据。 展开更多
关键词 变压器 励磁涌流 环流 零序分量
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含逆变型分布式电源和分支负荷的配电网自适应电流差动保护 被引量:2
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作者 王钢 冯婧桐 李杰 《电网技术》 EI CSCD 北大核心 2024年第6期2593-2602,I0099-I0102,共14页
电流差动保护具有良好的选择性和灵敏性。但是,逆变型分布式电源(inverter-interfaced distributed generator,IIDG)和分支负荷接入改变了配电网的故障特性,现有配电网的电流差动保护面临拒动或误动的风险。为解决以上问题,该文在计及P/... 电流差动保护具有良好的选择性和灵敏性。但是,逆变型分布式电源(inverter-interfaced distributed generator,IIDG)和分支负荷接入改变了配电网的故障特性,现有配电网的电流差动保护面临拒动或误动的风险。为解决以上问题,该文在计及P/Q控制的IIDG和分支负荷的故障等值建模基础上,从故障点、IIDG和分支负荷的相对位置出发,挖掘配电网线路两端正序电流差的幅值特征以及正序电流故障分量的相位特征。在此基础上,提出一种正序电流幅值与故障分量相角阈值配合的双比例制动系数自适应差动保护方案,并且利用幅相平面分析所提保护判据的可靠性和灵敏性。最后通过PSCAD/EMTDC验证了所提保护方案的有效性,仿真结果表明该方案适应不同故障类型、位置和过渡电阻,且不受IIDG以及分支负荷接入的影响。 展开更多
关键词 配电网 逆变型分布式电源 分支负荷 自适应电流差动保护 正序故障分量
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基于一种新型正弦幅值积分器的谐波检测方法 被引量:1
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作者 苗长新 祝宇航 +1 位作者 赵文鹏 刘家明 《电力系统保护与控制》 EI CSCD 北大核心 2024年第2期39-47,共9页
针对基于瞬时无功理论的ip-iq谐波检测法结构复杂、响应速度慢等问题,提出了一种采用改进正弦幅值积分器结构的谐波电流检测方法。首先,利用二阶广义积分器的输出滤波特性及正弦幅值积分器的极性选择特性,使其相结合构造出了一种滤波性... 针对基于瞬时无功理论的ip-iq谐波检测法结构复杂、响应速度慢等问题,提出了一种采用改进正弦幅值积分器结构的谐波电流检测方法。首先,利用二阶广义积分器的输出滤波特性及正弦幅值积分器的极性选择特性,使其相结合构造出了一种滤波性能更强,同时具有频率及极性选择作用的新型积分器。然后,利用该积分器快速准确地提取基波正序分量,并有效应用于谐波检测环节中。当电网电压存在直流偏置问题时,该积分器所构造的锁相环也能准确锁定电网频率及相位信息。最后,理论分析及仿真实验结果表明:该方法无需进行瞬时对称分量分离,就可提取出电网电压及负载电流基波的正负序分量,计算量小,谐波检测更精确。 展开更多
关键词 谐波检测 正弦幅值积分器 基波正序分量 直流偏置 锁相环
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